Yarn winding process and yarn package



1965 F. H. ENGELMAN ETAL 3,235,191

YARN WINDING PROCESS AND YARN PACKAGE Filed Aug. 29, 1963 2 Sheets-Sheet 1 RIMARY R B ON 5 P I B 4 l G. 3. Fl G. l. fly 7 AC 6 Q SECONDARY RIBBON l7 Hui FIG. 4.

' TERTIARY RIBBON FIG. 5.

INVENTORS FRANK L.LARKIN FREDERICK H. ENGELMAN BY 0% k AGENT Feb. 15, 1966 F. H. ENGELMAN ETAL 3,235,191

YARN WINDING PROCESS AND YARN PACKAGE Filed Aug. 29, 1963 2 Sheets-Sheet 2 RIBBON FREE WINDING PROCESS I8 BOBBIN RPM TERTIARY RIBBON RAT|O I450- 2 QUATERNARY RIBBON RATIO l |325--- 1 T (5 g l OCTONARY RIBBON RATIO I E |200- 1 l O n: PRIMARY RIBBON lO75- I i I 7WT7K7\7\| 7\ A A 7\ /T'l\'K K7Y7\7R7\ A'N7V7Y7T7Y7K7K7 9 5O L\LMA l/ /ALAL V \L\L\L BLAlJ/A/J/JUL \LMMAlJ/JL l9 CONSTANT AVERAGE TRAVERSAL SPEED 825- I I I I I I O 2 3 4 s e 7 RUN T|ME(HRS.)

YARN TAKE UP SPEED 733 YPM TRAVERSE CYCLE SPEED= 3O TPM AT 6 CPM AVERAGE TRAVERSAL SPEED= 990 TRAVERSALS PER MINUTE INVENTORS FRANK L. LARKIN F|G,2 FREDERICK H.ENGELMAN AGENT United States Patent 3,235,191 YARN WINDING PROCESS AND YARN PACKAGE Frederick H. Engelman and Frank L. Larkin, Pensacola, Fla., assignors to Monsanto Company, a corporation of Delaware Filed Aug. 29, 1963, Ser. No. 365,315 4 Claims. (Cl. 24218.1)

This invention relates to a process for winding filamentary and yarn materials and to the yarn package produced therefrom. More particularly, the invention relates to a yarn winding process wherein a regularly cycled traverse speed fluctuating about a constant average value is employed to effect a uniform yarn winding pattern permitting packaging larger than conventional yarn packages free or" primary and lower order ribbons.

The term ribbon as used here refers to a build-up of superimposed yarn windings or convolutions laid approximately one on top of the other which is characteristically formed at periodic intervals in a package of yarn wound on a yarn holder, bobbin, tube or the like by conventional yarn winding practices. The formation of ribbons in yarn packages is undesirable and disadvantageous. In unwinding yarn from a yarn package containing ribbons, as in the manufacture of fabric from yarn, the yarn convolutions slide or slough from and trap on the bobbin causing uneven takeoff tensions and consequent streaking in the fabric both in the griege and dyed states. Tension variations are also inherent in the yarn within the package when severe ribbons are present.

In a typical textile yarn winding practice, yarn is delivered from a spinning, drawing or other zone at a preselected speed to a take-up bobbin operatively driven by conventional means at a constantly variable rate of speed but maintaining a constant peripheral rate of speed for collecting the yarn at a constant rate of speed. Simultaneously during the collection of the yarn on the bobbin the yarn is displaced or traversed axially across the face of the bobbin by traversing means such as a reciprocable guide or a traverse groove roll at a constant rate of traversal. For purposes of convenient illustration let it be assumed that the rate of traverse of the yarn is 500 traversals per minute (t.p.m.), each traversal being equivalent to a back and forth displacement of the yarn across the bobbin by the traverse device; that the bobbin is four inches in diameter and that the bobbin is driven initially at 1,900 revolutions per minute (r.p.m.) and the r.p.m. progressively decreases for maintaining a constant peripheral bobbin rate of speed. As the yarn is packaged to a size where the total bobbin and package diameter equals eight inches the bobbin r.p.m. decreases to 500 r.p.m. The ratio of the traversal rate to the bobbin speed at any one time during the winding process will herein be referred to as the ribbon ratio. The ribbon ratio as start-up in the above example therefore is 50021000 or 1:2 and at completion 500:500 or 1:1 with an infinite number of ribbon ratios established therebetween. The ribbon ratio progressively increases from start-up to completion. It will be noted that at a ribbon ratio of 1:1 one traversal of yarn is made for each bobbin revolution and that at a ribbon ratio of 1:2 one traversal of yarn is made for a corresponding two revolutions of the bobbin.

An infinite number of ribbon ratios are encountered from start-up to completion of a yarn packaging process. At the point where the ribbon ratio is 2:3 each third traversal of yarn is superimposed forming a tertiary ribbon; a ribbon ratio of 3 :4 produces a quaternaiy ribbon wherein each fourth traversal is superimposed; a 4:5 ribbon ratio produces a quintary ribbon wherein every fifth traversal is superimposed; a 7:8 ribbon ratio produces an octonary ribbon; and ad infinitum. In the primary and secondary ribbon patterns the traversal rate bears a whole 3,235,191 Patented F eb. 15, 1966 ice number relationship to the bobbin r.p.m. whereas in the other classified ribbon patterns the traversal rate has a fractional relationship therewith and the latter ribbons are sometimes referred to as fractional ribbons.

In order for a ribbon to form at any ribbon ratio it is necessary that the specific ratio be maintained for a period of time. Since in a typical winding process the package diameter increases at a relatively slow rate there is a dwell time or short continuous period of time during which the bobbin rotates at approximately the same speed until a sufiicient amount of yarn is taken up to change the package diameter. Ribbon formation, therefore, is a result of a ribbon ratio maintained for a period of time. Generally, a formation of seven or more: superimposed convol utions produces an undesirable ribbon.

The speeds of 500 t.p.m. and 1,000 bobbin r.p.m. were chosen for purposes of convenient illustration only. In a typical process, a start-up t.p.m. to bobbin r.p.m. relationship is selected as a 5:9 ratio which would be evasive of the 1:2 ribbon ratio because it would not be practical to begin Winding with an undesirable buildup of yarn. Also, in this typical winding process the yarn package is ordinarily built only to the point where the primary ribbon ratio is confronted, as a yarn package containing a primary ribbon is not acceptable. Where it is desired to build a yarn package beyond the point where the primary ribbon is encountered and to circumvent the primary ribbon, the rate of traversal is controlled at a value below the bobbin r.p.m. However, this procedure causes the yarn to be wound at a non-uniform tension.

It is a primary object of this invention to provide a yarn winding process adapted to produce large yarn packages free of ribbons and having the yarn uniformly tensioned therethrough.

It is another object of this invention to provide .a yarn winding process adapted to produce a yarn package wound past the primary ribbon range at a constant average traversal rate of speed.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

In accordance with the novel process of the invention, a yarn is delivered at a preselected rate of speed to a yarn carrier such as a bobbin adapted to be driven at a varying decreasing rotational rate of speed or r.p.m. but maintaining a constant peripheral rate of speed for taking up the yarn at a constant rate. The yarn traveling to the bobbin is then displaced or traversed across the face of the bobbin at a regularly cycled speed fluctuating between a maximum positive value and a maximum equal negative value about a predetermined constant average traversal rate of speed and at a predetermined frequency to elude ribbon forming ratios. The yarn is packaged on the boibbin beyond the point where the bobbin rate of speed and the average traversal rate of speed bear a 1:1 ratio while always maintaining said average traversal rate of speed constant for forming a large ribbon free yarn package.

A better understanding of the novel winding process and of the package produced thereby will be gained by reference to the more detailed description which follows and to the accompanying drawing wherein:

FIGURE 1 is a schematic perspective view showing the novel winding process operated by appropriate textile draw winding equipment;

FIGURE 2 is a graph showing bobbin r.p.m. and yarn traversals per minute as a function of time and further illustrating the particular traversing cycling sequence in accordance with the invention;

FIGURE 3 is a developed plan view showing the traverse of yarn on a bobbin typifying the pattern of a primary ribbon;

FIGURE 4 is a developed plan view showing the traverse of yarn on a bobbin typi-fying the pattern of a secondary ribbon; and

FIGURE is a developed plan view showing the traverse of yarn on a bobbin typifying the pattern of a tertiary ribbon.

The novel winding process embodying the invention is illustrated in FIGURE 1 in conjunction with textile draw winding apparatus for carrying out the process. The yarn 1, such as nylon, extends from a suitable source thereof, for example cake 2, to a guide 3 and then to a feed roll assembly consisting of a driven feed roll 4 and a nip roll 5. The yarn is nipped between rolls 4 and 5 which are in surface engagement therebetween and is forwarded to a draw roll 6. The feed roll 4 is driven at one rate of speed and the draw roll 6 is driven at a higher rate of speed to stretch the yarn therebetween. A draw pin 7 is normally interposed between rolls 4 and 6 in the yarn path and one or several wraps are taken around pin 7 for localizing the attenuation of the yarn. Several common wraps are taken about the draw roll 6 and a separator roll 8 located near the draw roll. From the separator roll 8, the yarn travels to a traverse guide such as a driven traverse groove roll 9 and is laced within the traversing groove 10 formed about the circumference of roll 9 for traversing the yarn before the yarn is collected on a bobbin 11. Bobbin 11 is surfacely driven by a drive roll 12 powered by a motor 13 and is mounted on a shaft connected to one end of a lever 14 which is pivotally mounted at its opposite end. The drive roll 12 is driven at a constant speed and the bobbin 11 is driven at a progressively decreasing rate of speed inversely proportional to the increase in the diameter of the yarn package being wound on the bobbin. Thus, the bobbin 11 is driven so as to achieve a constant peripheral rate of speed.

Traverse groove roll 9 is driven through a shaft 15 connected to a standard type variable speed drive unit 16 that includes a controller 17 for sending a timed cycling signal to unit 16. The speed of shaft 15 can be varied over a wide range and controller 17 is adapted to permit cycling within specific desired ranges. Controller 17 may be provided with potentiometers that control the acceleration and deceleration rates and the amplitude within a selected cycle period, or suitable cam type controllers may be provided. Such a variable speed drive unit and controller are available as the Ajusto-Speed unit and controller from the Louis-Allis Company, Milwaukee, Wisconsin. I

According to an exemplary embodiment of the novel winding process which is graphically illustrated in the graph shown in FIGURE 2, after the yarn is laced as described within the draw winding apparatus, draw roll 6 is driven at a speed for delivering the yarn to bobbin 11 at approximately 812 yards per minute (y.p.m.). Bobbin 11 is initially driven at 1950 revolutions per minute (r.p.m.) as shown on the ordinate line of the graph for taking up yarn at approximately 733 y.p.m. Generally, the take-up speed is lower than the delivery speed because of normal shrinkage of the yarn. Thereafter, the bobbin rpm. decreases exponentially due to the increase in size of the package while the bobbin peripheral rate of speed remains at approximately 733 y.p.m. As the yarn package increases in size bobbin 11 pivots away from drive roll 12.. Line 13 in the graph represents the speed of the bobbin with respect to time shown as a seven hour packaging winding period and represented on the abscissa line of the graph.

Simultaneously while the yarn is being taken up on bobbin 11 the traverse groove roll 9 is driven at a cycled traverse speed providing an average rate of traverse of 990 traverses of the yarn across the face of the bobbin per minute which is achieved by proper adjustment of unit 16 and controller 17 and is indicated by line 19 in the graph. The groove roll 9 is cycled at a regular frequency of 6 cycles per minute with the traversal speed amplified to a positive m ximum of 1020 t.p.m. and to a ne ative maximum of 960 t.p.m. within each cycle in a saw-tooth pattern throughout the winding process. The amplitude is :30 rpm. about the average traversal speed of 990 t.p.m.

Ordinarily the various types of ribbons as noted in the graph would develop at the points indicated. However, with the yarn traverse speed cycled as described according to the invention the ribbon ratios are rippled through and the dwell time in a ribbon zone is insufficient to allow ribbon formation.

It is seen that the constant average of 990 t.p.m. is maintained throughout the winding period and that the package is wound with the bobbin rpm. higher than the constant t.p.m. up to the point of the primary ribbon and thereafter falls below the constant t.p.m.

It is important that the acceleration-dcceleration and deceleration-acceleration reversal of each cycle be made substantially instantaneously to form a saw-tooth pattern as represented in the graph (FIG. 2) to obtain a maximum differential traversal speed for a selected cycle amplitude and frequency at a uniform rate.

Winding processes according to the invention may be operated successfully within cycling ranges of 25l00 t.p.m. above and below, respectively, a predetermined average traversal rate of speed, that is :(25400) t.p.m., with cycling periods within a range of 4-10 cycles per minute. At higher winding speeds it is preferable that a relatively high amplitude and high frequency value be selected within the ranges indicated.

The winding process embodying the invention yields ribbon-free packages which are not limited in size by the primary ribbon and which are wound at a uniform tension. A yarn package having the yarn Wound under a uniform tension provides a yarn having a uniform shrinkage quality.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others and the article possessing the features, properties and the relation of elements which are exemplified in the description given. It will be understood that the invention is not contemplated to be limited to the preferred embodiment and that variations may be made within the scope of the following claims.

We claim:

1. A yarn winding process for forming large yarn packages free of ribbons comprising the steps of:

(a) delivering yarn at a preselected rate of speed to a yarn carrier means,

(b) collecting said yarn on said yarn carrier means,

(c) driving said yarn carrier means at a progressively decreasing rate of speed from a certain initial rate of speed to maintain a constant peripheral rate of speed,

(d) traversing said yarn back and forth across said yarn carrier means at a regularly cycled speed fluctuating between a maximum positive value and a maximum equal negative value about a redetermined average traversal rate of speeds, at a uniform and equal acceleration and deceleration rate providing a saw'tooth cycle, and at a predetermined frequency to elude ribbon forming ratios, and

(e) packaging said yarn on said yarn carrier means past the point where said carrier means speed and said average traversal speed establish a primary ribbon ratio while maintaining said average traversal rate of speed constant for forming a large ribbon free yarn package.

2.. A yarn Winding process for forming large yarn packages free of ribbons comprising the steps of:

(a) delivering yarn at a preselected rate of speed to a driven bobbin,

(b) collecting said yarn on said bobbin,

(0) driving said bobbin at a progressively decreasing rate of speed from a certain initial rate of speed to maintain a constant peripheral rate of speed,

(d) traversing said yarn back and forth axially across said bobbin at a cycled speed fluctuating at a predetermined value Within a range of 2Sl00 positive and Within an equal range of negative traversals per minute about a predetermined average traversal rate of speed, at a uniform and equal acceleration and deceleration rate providing a saw-tooth cycle, and at a frequency within a range of 4-10 cycles per minute to elude ribbon forming ratios, and

(e) packaging said yarn on said bobbin past the point Where the bobbin speed and said average traversal speed bear a 1:1 ratio while maintaining said average traversal rate of speed constant for forming a large ribbon free yarn package.

3. A yarn winding process as in claim 1 wherein, said maximum positive value and said maximum equal negative value are +30 t.p.m. and 30 t.p.m., respectively, and said predetermined frequency is 6 cycles per minute.

4. A package of yarn having a uniform shrinkage characteristic throughout its length, said package comprising:

(a) an elongated package core,

(b) yarn extending traversingly across said package core, at a predetermined constant average traversal rate per unit length of yarn,

(c) said traversals per unit length of yarn continually ((1) said yarn package being Wound to a size substantially past the primary ribbon forming dimension and being free of ribbons.

References Cited by the Examiner UNITED STATES PATENTS 2,571,694 10/1951 Dyer 24-2--18.1 X 2,763,824

9/1956 Bacheler 242l8.1 X

20 MERVIN STEIN, Primary Examiner. 

1. A YARN WINDING PROCESS FOR FORMING LARGE YARN PACKAGES FREE OF RIBBONS COMPRISING THE STEPS OF: (A) DELIVERING YARN AT A PRESELECTED RATE OF SPEED TO A YARN CARRIER MEANS, (B) COLLECTING SAID YARN ON SAID YARN CARRIER MEANS, (C) DRIVING SAID YARN CARRIER MEANS AT A PROGRESSIVELY DECREASING RATE OF SPEED FROM A CERTAIN INITIAL RATE OF SPEED, SPEDD TO MAINTAIN A CONSTANT PERIPHERAL RATE OF SPEED, (D) TRAVERSING SAID YARN BACK AND FORTH ACROSS SAID YARN CARRIER MEANS AT A REGULARLY CYCLED SPEED FLUCTUATING BETWEEN A MAXIMUM POSITIVE VALUE AND A MAXIMUM EQUAL NEGATIVE VALUE ABOUT A PREDETERMINED AVERAGE TRAVERSAL RATE OF SPEEDS AT A UNIFORM AND EQUAL ACCELERATION AND DECELARATION RATE PROVIDING A SAW-TOOTH CYCLE, AND AT A PREDETERMINED FREQUENCY TO ELUDE RIBBON FORMING RATIOS, AND (E) PACKAGING SAID YARN ON SAID YARN CARRIER MEANS PAST THE POINT WHERE SAID CARRIER MEANS SPEED AND SAID AVERAGE TRAVERSAL SPEED ESTABLISH A PRIMARY RIBBON RATIO WHILE MAINTAINING SAID AVERAGE TRAVERSAL RATE OF SPEED CONSTANT FOR FORMING A LARGE RIBBON FREE YARN PACKAGE. 